Immunoblot analysis of the structure of protein synthesis initiation factor eIF3 from HeLa cells.
Translational initiation factor eIF3 is a large, multisubunit protein complex involved in early steps of the initiation pathway. Affinity-purified polyclonal antibodies were used to analyze by immunoblotting the mass and charge characteristics of the subunits in HeLa cell lysates and in purified eIF3 preparations. The evidence indicates that eIF3 comprises at least seven antigenically distinct subunits: p170, p115, p66, p47, p44, p40, and p36. During purification, p170, p115, and p66 are partially degraded to smaller forms, which appear to be the major cause of variable subunit composition among preparations of eIF3.
Milburn
S C
SC
Department of Biological Chemistry, School of Medicine, University of California, Davis 95616.
Duncan
R F
RF
Hershey
J W
JW
D000906:Antibodies / Q000302:isolation & purification; D002846:Chromatography, Affinity; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D039621:Eukaryotic Initiation Factor-3; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting / Q000379:methods; D008970:Molecular Weight; D010448:Peptide Initiation Factors / Q000032:analysis* / Q000302:isolation & purification
D000906:Antibodies; D039621:Eukaryotic Initiation Factor-3; D010448:Peptide Initiation Factors